Facsimile recorder printer bar



y 13, 1950 w. G. H. FINCH ET AL 2,515,864

FACSIMILE RECORDER PRINTER BAR Filed Dec. 17, 1946 J6 J 22 f2 12 4110 I: I P 24 3 FIG.3.

ENLfIREED VIEW JPPE'GX. DOUBLE SIZE ATTORNEYS Patented July 18, 1950 UNITED STATES PATENT OFFICE fried H. Hohmann, Bronx, N. Y., assignors, by mesne assignments, to Pierce Company, Providence, R. I.

Application December 17, 1946, Serial No. 716,774

1 Claim. 1

Our present invention relates to facsimile scanning devices and more particularly to facsimile scanning devices of the type utilizing a knife edge or blade cooperating with a bead or wire helically arranged on a drum.

The type of scanning operation for which my invention is designed is thus of the general character shown in the application Serial No. 554,427, now Patent No. 2,413,962, issued January '7, 1947.

Our present invention relates primarily to the forms and support of the knife blade itself so that it may readily be mounted, adjusted, and replaced in the machine and so that it will always engage the helical bead properly to make a perfect impression.

Hertofore in the construction and operation of helical recorders utilizing a knife blade engaging a helical bead on a drum, various attempts have been made to obtain the proper recording pressure and engagement. The greatest difficulty which arises is the necessity for having an extremely light blade so that ordinary springs may readily retain the same in engagement with the helical head at all points of contact and where the inertia of the blade itself will not prevent the springs from constantly maintaining such contacts. Also, such difficulties have arisen from the fact that where extremely light blades were used, they tended to be flexible and, therefore,

bent around the bead itself thereby thickening the recording line unnecessarily.

Where a very thin blade was used, relying on the width of the blade for stiffness, the blade nevertheless tended to bend and this bending of the blade caused the blade to bow out so that the recording line instead of being a straight line on the paper was a bowed line, and the recording operation was performed not by the edge of the blade but rather by the side of the edge of the blade at the center of the blade and by the edge of the blade itself at the two ends of the blade.

This, apart from interfering with the clarity of the recording, tended quickly to crystallize and destroy the blade itself. An object of our invention is the provision of a novel knife blade for a helical scanning system wherein the knife blade may readily be made rigid and wherein the construction of the elements lends itself to rigidification.

Another object of our invention is the provision of novel mounting means for the knife blade in the helical scanning system whereby the knife blade itself is resilientl mounted while, nevertheless, the blade as a whole acts as a single stiff member.

Another object of our invention is the provision of novel supporting means whereby a stiff blade may be resiliently mounted with respect to a helical Scanning system so that the blade will at all times maintain perfect contact with the helical scanning bead at ever position thereof without bending or flexing in order to maintain such contact.

The foregoing and many other objects of our invention will become apparent in the following descriptions and drawings in which Figure 1 is a top view of a portion of a facsimile recorder embodying my novel knife blade support.

Figure 2 is a side view of the portion of the facsimile recorder of Figure 1 taken from line 2-2 of Figure 1.

Figure 3 is a cross-sectional view taken on line 3-3 of Figure 1 looking in the direction of the arrows.

Figure 4 is a cross-sectional view taken on line l-4 of Figure 1 looking in the direction of the arrows.

Figure 5 is a top view taken from line 5-5 of Figure 1 showing a modified means for clamping the knife blade in place.

Figure 6 is a view corresponding essentially to that of Figure 1 showing a slightly modified method for supporting the knife blade in position.

Figure 'l is an end view of the modification of Figure 6 showing the support in greater detail.

Figure 8 is a modified view of an alternative knife blade support.

Figure 9 is a cross-sectional view taken on line 9 taken on Figure 8 looking in the direction of the arrows.

Referring now to Figures 1, 2, 3, and 4 our novel recording system comprises a knife Ill preferably of a Z-shaped form having a main portion H and blade elements, [2, I2. Either of the blade elements l2 may be mounted in the support so as to cooperate with the bead E5 on the drum I6.

The method of operation is then generally in accordance with the principles set forth in application Serial No. 554,427.

As above pointed out, however, it is necessary that the blade be made as rigid as possible while, nevertheless, it be resiliently mounted so that it may press against the bead l5 at every position of the bead. This has been a real problem in facsimile recording because the point of contact with the bead moves rapidly from one end of the blade to the other.

In a recording done at lines per inch and one inch per minute at this point of contact thus moves across the knife blade from one end to the other 100 times a minute. Accordingly, theblade must be light; it must be rigid, and the supporting means must be such as to maintain even contact at every point.

For this purpose my novel blade in is mounted in a novel support 20, which support in turn is carried in any appropriate manner as by the screws 2| on a cross bar 22 which in turn is carried on a frame member 23,1-.thesaidxframe member 23 being pivotally supported at pivots 28 so that the entire assembly, including .;the knife blade, may be swung out of the engagement with the drum 16 to permit the changing of blades Ill and the loading or adjustment of the machine.

The support 20 is provided with a pair of threaded openings 22, 22 adjacent the ends of the support with said openings being directed toward the knife blade. The openings. 22.:are threaded and receive .the screws 23, 23,' which screws may be adjusted either by a screw driver enteringthe slot-24 ormay be adjusted by a socket wrench wherenthe ends of the screws aresquared off.

'lTl'lG'SCIGWS 23 carry-at'theend thereof the springs. 26,-25- which emerge from the openings 22 and bear against the under surface of the main body portion H of the knife blade 15, thus biasing the knife blade iii and its: scanning edge l2 against the bead-i5. The'supportfillisralso provided with the notch. 28in which the blade portion l2a, which is not used for-scanning purposes at the time, rests.

:The support also is provided with? theretaining-.memberstfid, 38 which are "held :in position on the threaded bolts 3! by operringsffirtherein which rest on" the said bolts. The retaining members" 30 may be tightened" in: retainingposition by the knurled nut 33 threaded on thebolt 3|-and encasing' the body portion 350i each-retaining member 38 betweenithe nut: and; the side of the support 20.

"Twosuch retaining members'tll are used. The said retaining members each have a reentrant flange 38 extending over 'the notch"28. 'The blade 10 maythus be readily mounted inposition by being slid in from the end. The blade element In is slid into the end of the notch 28,while -the shoulderdfi between theblade-element 12a and the main body I! of the blade it is "slid under thereentrant flange 38 on one side, the body portion ll of the blade being at theJsame time slid over the end of thespringZB which is pushed down for this purpose.

The entire blade I is then slid over until the end thereof reaches theopposite retaining member 38,- at which time the shoulder 443 is slidunder'the flange 38 on that side and the body :portion H is slid over the spring'26'on thatside. The blade I0 is thus mounted in position where the springs 26 bias the same towardthe drum so that the blade portion l2 contacts thebead I of the drum. Thereentrantflange'tfi of the retaining members '30 prevents the blade Hi from being pushed out of the support.

At the same time, the bead it pushes the blade portion 62 of the knife member Ill backaga'inst the supportzt, this force being resisted by the springs 2fiwhich thus bias the blade portion E2 of the knife *member it) against the bead 5. The construction of the knife member i0 is such as to rigidify' the same against. bending or howing. The blade elements I'Zare. made extremely short with respect to the main body portion so t that the rigidity obtained by the bends at 40 and 4| is imparted to the blade itself.

Thus, in a practical commercial device, each of the blade elements l2 and 12a is one eighth of an inch high, while the base portion II is approximately one half an inch wide and the gauge of metal which is sufliciently-small :to be consistent with markings of 100 lines to an inch.

It will be obvious that many modifications of the basic principles herein disclosed may be used.

"Where additional rigidity is required even though the conformationof the blade produces all the rigidity that .should be necessary, additional ri- .gidifying pieces; 5Bmay be secured in any suitthat theywill not interfere with the operation of the spring 26 as shown.

.These ,rigidifying strips 56 are -indicated 1 .in

dotted lines since for all ordinary applications they are not necessary. The conformation of the blade provides sufficient rigidity. 'It will also be obvious that the blade elements I2 and 120,. may be formed to enhance their rigidity. Thus, they may be longitudinally corrugatedor they may be made partially tubular in form, or they may be given an I-beambross-section with one of the legs of the I being extended .to form the blade or additional rigidifying strips or tubes may be secured to .theblade elements l2 and i 2a.

Also, it will be obvious that. the retainer members 30 with'their reentrant flanges 38 need not necessarily be individual pieces as shown but may be a continuous strip extending along the entire support. Also, in addition to the. supporting' means shown in Figures 1 to 4, the blade may be further supportedby a clamp member which is. rotatable 5i entering the slot 52, the said rotatable member 5! being rotatably mounted on the stud 53 in the support 20.

The conformation of the rotatable member 5! permits the slot 52in the blade. Ida to be slipped therefrom, and thenthe rotatable member 5! may be rotated to clamp the blade la in position. This is preferably \usedinconnection with the securingelement shown in-Figures .l .to l, although this form of .securement may be used in place of the retaining membersttnf Figures 1 to 4.

In Figures 6 .and '7, we have shown a modified form of securement .and supportfor any blade. The blade I. ll); here shown has substantially the constructionof blade. [0 of Figures 1 to.5. This blade, however, is..provided .withtheextending pin! l I at all four corners.

The support I20 has substantially the form previously descri-bedin connection-with support 20 of Figures v1 to 5, but the support I20 does not have a notch nor does it have retaining members 30. The support I28 is,.however,.provided with springs IZB-which operate in the same manner as previously described.

The elements which mount. the knife bladev i It on the support I29 are the sidesecurement members llll which are secured .to theends of :the support I20 by screws I02. The securementmembers IOI have upstanding legs Hi3 and I84. Leg I03 is provided with an opening M5 to receive the pin HI in such manner that the blade H5 is pivotally supported at the edge of the blade member H0 opposite the knife edge H2.

By providing the pins III at all four corners of the blade member I l D, it is possible to. reverse the blade when one of the blade elements is worn out. Leg I04 is provided with the reentrant flange I06; the two reentrant flanges at each end of the support I20 thus prevent the blade member I I from being forced entirely out of position by the springs I26 and limit the movement of the blade member H0 in response to the springs I26.

Flanges I06 are so proportioned, however, that the bead of the drum when it bears against the blade or edge I I2 of the blade member I I0 forces the member I I0 against the springs I26 and away from the flanges I06. It will, thus, be seen that in order to mount the blade member I I0 in position, it is necessary to loosen the screw I02 sufficiently to permit the pins III to be introduced into the opposite holes I05 and then to tighten the screw I02. This need merely be done on one side.

The form of Figures 6 and 7 thus requires a slight degree of manipulation in order to mount or replace a knife blade and also requires that pins III be soldered or otherwise secured to the knife blade. However, the construction thereof is simple and operative although the construction of Figures 1 to 4 is preferred.

In Figures 8 and 9 I have shown a still further modified and preferred form of knife blade mounting. The blade here used iS identical with the blade I0 of Figures 1 to 4.

A mounting support 220 is an angularly bent metallic member having a face 20I, a base 202, and an opposite vertical member 203, the three elements, 20I, 202, and 203, forming a U-shaped channel-like construction.

A retaining panel 204 is bent up at 205 from the element 203 and is so arranged that its edge 206 terminates adjacent the end 201 between elements 20I and 202 of the channel-like support 220. Leaf spring members 2I0, 210 are mounted in suitable supports 2H, 2 in the section 203 of the support member 220. The said leaf springs may simply consist of screened wire, one end of the spring being caught in one of the supports 2 and being slidable with respect to the other.

The upper loops 2I2, 2I2 of the springs 2I0 project outwardly through the slots 2I5 in the retaining member 204 to bear against the back of the support element 2!". It will thus be seen that the blade I0 may be slid into the support element 220 from the side, the leg I2a thereof entering between the edge 206 of section 204 of the support and the base 202 of the support and the main section II of the blade I0 extending in surface-to-surface engagement with the face 20I of the support and being held in engagement therewith by the springs 2I0.

By this means, therefore, a simplified support is provided in a one-piece construction which permits the blade I0 to be slidably inserted and removed, reversed and replaced. The curve at 2I2 of the springs 2I0 ermits this sliding action to occur without any manipulation of any kind whatever, and the supporting member is of simple construction and formation. The support memher 220 may have any suitable piece of insulating material secured thereto in any appropriate manner in order to facilitate the mounting of the support and blade I0 which it carries on the frame or any other portion of the facsimile recorder.

In the foregoing, we have described our invention only in connection with a specific preferred embodiment thereof. Many variations and modifications of our invention should now be obvious to those skilled in the art. Accordingly, we prefer to be bound not by the specific disclosures herein contained, but only by the appended claim.

We claim:

In a facsimile receiver comprising a scanning system including a rotatable drum; a helical bead on said drum; a printing bar engaging said bead; said printing bar extending longitudinally of said drum parallel to the axis thereof and having a substantially Z-shaped cross section; the longitudinal elements forming the top and bottom of the 2 being of the order of one-eighth inch in width and the longitudinal element forming the main body of the Z being of the order of one-half inch in width.

WILLIAM G. H. FINCH. GOTTFRIED I-I. HOHMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,227,109 Shankweiler Dec. 31, 1940 2,380,467 Ressler July 31, 1945 2,413,962 Finch Jan. 7, 1947 2,415,229 Young Feb. 4, 1947 

